We compile JWST/NIRSpec prism and MIRI data for 249 Little Red Dots (LRDs) at 2.3<z<9.3, forming a representative spectroscopic subset of NIRCam-selected LRDs. We derive a median stacked spectrum covering rest-frame 0.09-1.2 μm, with MIRI photometry extending the spectral energy distribution to 4 μm. Four additional stacks for subsamples defined by optical-to-UV luminosity ratios show that LRDs form a heterogeneous population spanning diverse continuum slopes and line properties. Assuming LRDs host super-massive black holes (BHs) surrounded by dense gas clouds, and stars accompany this core, we infer masses of M_BH∼10^6.0-6.5 M_⊙ and M_∼10^8.3 M_⊙, corresponding to BH-to-stellar mass ratios of 1-2

Our understanding of the physical properties of star-forming galaxies during the Epoch of Reionization (EoR; at z > 6) suffers from degeneracies among the apparent properties of the stars, nebular gas, and dust. These degeneracies are most prominent with photometry, which has insufficient (1) spectral resolution and (2) rest-frame spectral coverage. We explore ways to break these degeneracies with a sample of N = 22 high-redshift star-forming galaxies at 7 < z(phot) <= 9, using some of the deepest existing imaging from JWST/NIRCam and JWST/MIRI with JADES. Key to this study is the imaging from JWST/MIRI at 7.7 mu m, which provides coverage of the rest-frame I band at the observed redshifts. We infer stellar population properties and rest-frame colors using a variety of filter sets and star formation history (SFH) assumptions to explore the impact of these choices. Evaluating these quantities both with and without the 7.7 mu m data point shows that dense spectral coverage with JWST/NIRCam (eight or more filters, including at least one medium-band at lambda(obs) approximate to 4-5 mu m) can compensate for lacking the rest-frame I-band coverage for the vast majority (approximate to 80%) of our sample. Furthermore, these galaxy properties are most consistently determined by assuming the delayed-tau SFH, which provides the smallest offsets and scatters around these offsets when including JWST/MIRI. Within extragalactic surveys like JADES and CEERS, our findings suggest that robust characterization of the stellar population properties and rest-frame colors for typical high-redshift star-forming galaxies (i.e., galaxies with M-UV approximate to -20 and beta(UV) approximate to -2) is possible with JWST/NIRCam alone at z approximate to 8.

ABSTRACT The discovery of high-redshift galaxies exhibiting a steep spectral ultraviolet (UV) downturn potentially indicative of two-photon continuum emission marks a turning point in our search for signatures of star formation following a top-heavy initial mass function in the early Universe. We develop a photometric search method for identifying further nebular-dominated galaxy candidates, whose nebular continuum dominates over the starlight, due to the high ionizing photon production efficiencies $\xi _\mathrm{ion}$ associated with massive star formation. We utilize the extensive medium-band imaging from the JWST Advanced Deep Extragalactic Survey (JADES), which enables the identification of Balmer jumps across a wide range of redshifts ($1.5 \lt z \lt 8.5$), through the deficit in rest-frame optical continuum level. As Balmer jumps are a general recombination feature of young starbursts ($\lesssim 3$ Myr), we further demand a high observed $\log \, (\xi _\mathrm{ion, obs}/\mathrm{(Hz\ erg^{-1})}) \gt 25.60$ to power the strong nebular continuum, together with a relatively non-blue UV slope ($m_\mathrm{F115W}-m_\mathrm{F200W} \gt -0.4$ at $z=6$) indicating a lack of stellar continuum emission. Our nebular-dominated candidates, constituting ${\sim }11$ per cent of galaxies at $z \sim 6$ (decreasing to ${\sim }2$ per cent at $z \sim 2$, not completeness-corrected) are faint in the rest-frame optical (median $M_\mathrm{opt} = -17.95$) with extreme line emission (median $\mathrm{EW}_\mathrm{H\alpha , rest} = 1567$ Å, $\mathrm{EW}_\mathrm{[O\ III] + H\beta ,rest} = 2292$ Å). However, hot H ii region temperatures, collisionally enhanced two-photon continuum emission, and strong UV lines are expected to accompany top-heavy star formation. Thus nebular-dominated galaxies do not necessarily exhibit the biggest Balmer jumps, nor the largest $\xi _\mathrm{ion, obs}$ or reddest UV slopes. Hence continuum spectroscopy is ultimately required to establish the presence of a two-photon downturn in our candidates, thus advancing our understanding of primordial star formation and active galactic nucleus.

The unexpectedly high abundance of galaxies at z > 11 revealed by JWST has sparked a debate on the nature of early galaxies and the physical mechanisms regulating their formation. The Atacama Large Millimeter/submillimeter Array (ALMA) has begun to provide vital insights on their gas and dust content, but so far only for extreme 'blue monsters'. Here we present new, deep ALMA observations of JADES-GS-z11-0, a more typical (sub-L^*) z > 11 galaxy that bridges the discovery space of JWST and the Hubble Space Telescope. These data confirm the presence of the [O III] 88 μm line at 4.5σ significance, precisely at the redshift of several faint emission lines previously seen with JWST/NIRSpec, while the underlying dust continuum remains undetected (F_ν< 9.0 μJy), implying an obscured star formation rate (SFR) of SFR_IR≲ 6 M_⊙ yr^-1 and dust mass of M_dust≲ 1.0 × 10^6 M_⊙ (all 3σ). The accurate ALMA redshift of z_[O III] = 11.1221 ± 0.0006 (≳ 5× refined over NIRSpec) helps confirm that redshifts measured purely from the Lyman-α break, even spectroscopically, should properly take into account the effects of potential damped Lyman-α absorption (DLA) systems to avoid systematic overestimates of up to Δz ≈ 0.5. The [O III] 88 μm luminosity of L_[O III] = (1.0 ± 0.3) × 10^8 L_⊙, meanwhile, agrees well with the scaling relation for local metal-poor dwarfs given the SFR measured by NIRCam, NIRSpec, and MIRI. The spatially resolved MIRI and ALMA emission also underscores that JADES-GS-z11-0 is likely to consist of two low-mass components that are undergoing strong bursts of star formation yet are already pre-enriched in oxygen ( 30

JWST is beginning to uncover a population of extremely metal-poor galaxies (EMPGs, Z < 1% Z_⊙) at z > 3, mostly through serendipitous NIRSpec discoveries and blind slitless spectroscopy. To accelerate our understanding of pristine star formation, we further develop a methodology to identify EMPG candidates from photometry, using the extensive deep medium-band imaging from JADES. Our EMPG candidates at 2.5 < z < 6.5 exhibit strong photometric boosts by Hα, yet correspondingly weak boosts by [O III] + Hβ, likely indicating extremely low metallicity to explain their lack of [O III] emission. We further demand our EMPG candidates to have strong Balmer jumps, as revealed by medium-band imaging, to ensure that they are young starbursts, as opposed to broad-line AGN/LRDs, though contamination by dusty/dense-gas starbursts and highly-obscured AGN remains a concern. SED-fitting with near-pristine models (∼0.1-1% Z_⊙) indicates that our 22 EMPG candidates are low-mass (median M_* ≈ 10^6.7 M_⊙), faint dwarf galaxies (M_UV≈ -16.6), with high ionizing photon production efficiencies (log (ξ_ion, obs/(Hz erg^-1)) ≈ 26.0). Hence these are plausible sites of near-pristine star formation, comprising ∼0.04-0.6% of 2.5 < z < 6.5 galaxies at -19 < M_UV < -16. We discuss this extremely metal-poor extension to the mass-metallicity relation. We forecast that deep (∼28 h) NIRCam slitless spectroscopy can identify bright EMPGs through strong Hβ but lack of [O III] emission, or secure the redshifts of fainter systems through Hα detections. Highly-multiplexed NIRSpec spectroscopy offers an alternate route to discovering the faintest pristine galaxies out to z=10, without requiring deep medium-band/MIRI imaging to identify secure candidates.

We report the confirmation of a HeIIλ1640 emitter located at 3 pkpc from the galaxy GN-z11, at z=10.6. The detection, based on JWST NIRSpec-IFU high-resolution spectroscopy, confirms a previous claim based on medium-resolution spectroscopy. The HeIIλ1640 identification is further supported by the independent detection of Hγ obtained by Übler et al. (2026) at the same location. The HeII emission is spectrally resolved in two components separated by 120 km/s. The Equivalent Width of the HeII emission is extremely high (>20 A). No metal lines are detected. Population III stars appear to be the most plausible explanation for the observed HeII emission. We argue that Population III stars are the most plausible explanation for the observed He II emission, with no satisfactory alternative from other classes of sources or mechanisms.

Wisps are among the most prominent scattered light artifacts in JWST/NIRCam imaging. They often appear in certain regions of the detectors and contaminate observations at surface-brightness levels relevant for faint-source photometry. We introduce a new subtraction method that uses the non-negative matrix factorization (NMF) algorithm to model and remove wisps. Using deep NIRCam observations from the JWST Advanced Deep Extragalactic Survey (JADES) and other programs, we construct multi-component, filter- and detector-specific wisp templates that capture the wisp structures and their exposure-to-exposure morphological variations. Wisps in individual exposures are represented as non-negative linear combinations of these templates, consistent with their additive nature and reducing degeneracies relative to single-template scaling. Compared to existing approaches, our method delivers lower residual root mean square in wisp-affected regions and reduces photometric bias and scatter to levels consistent with clean detector areas. The NMF wisp templates are readily applicable to other datasets and are publicly released to support future NIRCam extragalactic surveys.

We present the UV-to-near-IR (NIR) size evolution of a sample of 161 quiescent galaxies with M-* > 10(10)M(circle dot)over 0.5 < z < 5. With deep multiband NIRCam images in GOODS-South from JADES, we measure the effective radii (R-e) of the galaxies at rest-frame 0.3, 0.5, and 1 mu m. On average, we find that quiescent galaxies are 45% (15%) more compact at rest-frame 1 mu m than they are at 0.3 mu m (0.5 mu m). Regardless of wavelengths, the R-e of quiescent galaxies strongly evolves with redshift, and this evolution depends on stellar mass. For lower-mass quiescent galaxies with M-* = 10(10)-10(10.6)M(circle dot), the evolution follows R-e proportional to (1 + z)(-1.1), whereas it becomes steeper, following R-e proportional to (1 + z)(-1.7), for higher-mass quiescent galaxies with M-* > 10(10.6)M(circle dot). To constrain the physical mechanisms driving the apparent size evolution, we study the relationship between R-e and the formation redshift (z(form)) of quiescent galaxies. For lower-mass quiescent galaxies, this relationship is broadly consistent with R-e proportional to(1+z(form))(-1) , in line with the expectation of the progenitor effect. For higher-mass quiescent galaxies, the relationship between R-e and z(form) depends on stellar age. Older quiescent galaxies have a steeper relationship between R-e and z(form) than that expected from the progenitor effect alone, suggesting that mergers and/or post-quenching continuous gas accretion drive additional size growth in very massive systems. We find that the z > 3 quiescent galaxies in our sample are very compact, with mass surface densities Sigma(e) greater than or similar to 10(10)M(circle dot) kpc(-2), and their R-e are possibly even smaller than anticipated from the size evolution measured for lower-redshift quiescent galaxies. Finally, we take a close look at the structure of GS-9209, one of the earliest confirmed massive quiescent galaxies at z(spec) similar to 4.7. From UV to NIR, GS-9209 becomes increasingly compact, and its light profile becomes more spheroidal, showing that the color gradient is already present in this earliest massive quiescent galaxy.

We study the luminosity function (LF) and clustering properties of 888 H alpha emitters (HAEs) at 3.75 < z < 6 in the GOODS-N field. The sample, built from JWST CONGRESS and FRESCO NIRCam grism surveys using a novel redshift assignment algorithm, spans similar to 62 arcmin(2) and reaches L-H alpha similar to 10(41.2) erg s(-1). We identify two prominent filamentary protoclusters at z approximate to 4.41 and z approximate to 5.19, hosting 98 and 144 HAEs, respectively. The observed H alpha LFs show similar shallow faint-end slopes for both protocluster and field galaxies at 3.75 < z < 5, and for the protocluster at 5 < z < 6 (alpha approximate to -1.2 to -1.3). In contrast, the field LF at 5 < z < 6 has a much steeper slope ( alpha=-1.87(-0.23)(+0.30)), suggesting that protocluster galaxies at z > 5 are more evolved, resembling the populations at 3.75 < z < 5. The observed star formation rate density from H alpha integrated down to 0.45 M-circle dot yr(-1), is 0.050(-0.003)(+0.002)M(circle dot)yr(-1)Mpc(-3) at 3.75 < z < 5 and 0.046(-0.004)(+0.006)M(circle dot)yr(-1)Mpc(-3) at 5 < z < 6, with protoclusters contributing about 25% and 55%, respectively. This implies a large fraction of star formation at z > 4 occurs in protoclusters. For the first time, we conduct the star formation-rate-limited three-dimensional clustering analysis at z > 4. We find that the filamentary geometry of protoclusters flattens the power-law shape of the HAE autocorrelation functions, with slopes much shallower than the typically assumed value. The autocorrelation function of field HAEs has a correlation length of r(0)=4.61(-0.68)(+1.00)h(-1)Mpc at z approximate to 4-5 and r0(=)6.23(-1.13)(+1.68)h(-1)Mpc at z approximate to 5-6. Comparing the observed correlation functions with the UniverseMachine simulation, we infer the dark matter (sub-)halo masses of HAEs to be log(M-h/M-circle dot)=11.0-11.2 at z approximate to 4-6, with a scatter of 0.4 dex.

ABSTRACT Understanding how galaxies assemble their mass during the first billion years of cosmic time is a central goal of extragalactic astrophysics, yet joint constraints on their sizes and kinematics remain scarce. We present one of the first statistical studies of the $\mathrm{H}\alpha$ size–mass relation at high redshift with a sample of 213 galaxies at spectroscopic redshifts of $z\approx 4-6$ from the FRESCO and CONGRESS NIRCam grism surveys. We measure the $\mathrm{H}\alpha$ morphology and kinematics of our sample using the novel forward modelling Bayesian inference tool geko, and complement them with stellar continuum sizes in the rest-frame far ultraviolet (FUV), near ultraviolet (NUV), and optical, obtained from modelling of imaging data from the JADES survey with Pysersic. At $z\approx 5$, we find that the average H $\alpha$ sizes are larger than the stellar continuum (FUV, NUV, and optical), with $r_{\rm e, \mathrm{H}\alpha } = 1.17 \pm 0.05$ kpc and $r_{\rm e,cont} \approx 0.9$ kpc for galaxies with $\log (M_{\star } \rm [{\rm M}_{\odot } ]) = 9.5$. However, we find no significant differences between the stellar continuum sizes at different wavelengths, suggesting that galaxies are not yet steadily growing inside–out at these epochs. Instead, we find that the ratio $r_{\rm e, \mathrm{H}\alpha }/r_{\rm e, NUV}$ increases with the distance above the star-forming main sequence ($\Delta \rm MS$), consistent with an expansion of H $\alpha$ sizes during episodes of enhanced star formation caused by an increase in ionizing photons. As galaxies move above the star-forming main sequence, we find an increase of their rotational support $\text{v}/\sigma _0$, which could be tracing accreting gas illuminated by the $\mathrm{H}\,\alpha$ emission. Finally, we find that about half of the elongated systems ($b/a\lt 0.5$) are not rotationally supported, indicating a potential flattened/prolate galaxy population at high redshift.

The Milky Way Backup Program (MWBP), a survey currently underway with the Dark Energy Spectroscopic Instrument (DESI) on the Nicholas U. Mayall 4 m Telescope, works at the margins of the DESI Main surveys to obtain spectra of millions of additional stars from the Gaia catalog. Efficiently utilizing times between ∼12° and 18° twilight and poor weather conditions, the MWBP extends the range of stellar sources studied to both brighter magnitudes and lower Galactic latitude and declination than the stars studied in DESI’s Main Milky Way Survey. While the MWBP prioritizes candidate giant stars selected from the Gaia catalog (using color and parallax criteria), it also includes an unbiased sample of bright stars (i.e., 11.2 ≲ G < 16 mag) as well as fainter sources (to G ≲ 19 mag). As of 2025 March 1, the survey had obtained spectra of ∼7 million stars, approximately 1.2 million of which are included in the DESI Data Release 1. The DESI spectra cover the wavelength range from 3600 to 9800 Å at a resolution λ /Δ λ varying from 2000 to 5000. The full survey, when completed, will cover an area of more than 21,000 deg ^2 and include approximately 10 million Gaia sources, roughly equal to the number of stellar spectra obtained through the DESI Main Survey, while only utilizing ≈9% of all DESI observing time. This paper provides an overview of the MWBP, describing the target selection, observing strategy, and an introduction to the resulting data.

We analyze two dusty star-forming galaxies at z = 6.6. These galaxies are selected from the ASPIRE survey, a JWST Cycle 1 medium program, and the Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 9 large program targeting 25 quasars and their environments at z similar or equal to 6.5-6.8. These galaxies are identified as companions to UV-luminous quasars and robustly detected in ALMA continuum and [C ii] emission, yet they are extraordinarily faint at the NIRCam wavelengths (down to >28.0 AB mag in the F356W band). They are more obscured than galaxies like Arp220 (A(V) up to similar to 7.5 mag), and thus we refer to them as "NIRCam-dark" starburst galaxies (star formation rate similar or equal to 80-250 M-circle dot yr(-1)). Such galaxies are typically missed by (sub)-millimeter blank-field surveys. From the star formation history (SFH), we show that the NIRCam-dark galaxies are viable progenitors of massive quiescent galaxies at z greater than or similar to 4 and descendants of UV-luminous galaxies at z > 10. Although it is hard to constrain their number density from a quasar survey, we conclude that NIRCam-dark galaxies can be as abundant as n similar to 10(-5.5) Mpc(-3) assuming a light halo occupation model. If true, this would equal to similar to 30% of the number densities of both the quiescent galaxies at z greater than or similar to 4 and UV-luminous galaxies at z > 10. We further predict that analogs at z similar to 8 should exist according to the SFH of early massive quiescent galaxies. However, they may fall below the current detection limits of wide JWST and ALMA surveys, and thus remain "JWST-dark." To fully trace the evolution of massive galaxies and dust-obscured cosmic star formation at z greater than or similar to 8, wide-field JWST/NIRCam imaging and slitless spectroscopic surveys of early protoclusters are essential.

We present the galaxy stellar population catalogue from the JWST Advanced Deep Extragalactic Survey (JADES) Data Release 5 (DR5), providing homogeneous Bayesian inference of physical galaxy properties in GOODS-N and GOODS-S. Using deep JWST/NIRCam and MIRI imaging combined with ancillary multi-wavelength data, we model the spectral energy distributions of 500,000 sources with the Prospector framework. Our modelling incorporates flexible non-parametric star-formation histories (SFHs), nebular emission, dust attenuation, metallicities, and mid-infrared AGN and dust emission. We adopt an evolving star-forming main sequence (SFMS) prior for modelling the SFHs, which provides a physically-motivated long-term shape of SFHs while retaining non-parametric flexibility. The prior links stellar mass growth and SFR through the observed redshift-dependent SFMS, shaping the global behaviour of the inferred SFHs but allowing substantial deviations and scatters wherever supported by the data. We derive posterior distributions for stellar masses, SFRs, SFHs, dust attenuation, metallicities, and AGN contributions. The depth and wavelength coverage of JADES enable robust stellar mass measurements down to low-mass limits, as well as improved constraints on recent star-formation activity for 350,000 galaxies at z = 1 - 9. The adoption of a physically motivated prior mitigates unphysical solutions and reduces degeneracies between redshift, age, dust, and metallicity, particularly for faint sources. We validate the catalogue through consistency checks and comparison to spectroscopic redshifts where available. The resulting value-added catalogue provides a uniform set of stellar population parameters suitable for statistical studies of galaxy growth, quenching, and the build-up of stellar mass across cosmic time. The full catalogue and posterior summaries are publicly released as part of JADES DR5.

We present an overview of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey (JADES), an ambitious program of infrared imaging and spectroscopy in the GOODS-S and GOODS-N deep fields, designed to study galaxy evolution from high redshift to cosmic noon. JADES uses about 770 hours of Cycle 1 guaranteed time largely from the Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec) instrument teams. In GOODS-S, in and around the Hubble Ultra Deep Field and Chandra Deep Field South, JADES produces a deep imaging region of ~45 arcmin$^2$ with an average of 130 hrs of exposure time spread over 9 NIRCam filters. This is extended at medium depth in GOODS-S and GOODS-N with NIRCam imaging of ~175 arcmin$^2$ with an average exposure time of 20 hrs spread over 8-10 filters. In both fields, we conduct extensive NIRSpec multi-object spectroscopy, including 2 deep pointings of 55 hrs exposure time, 14 medium pointings of ~12 hrs, and 15 shallower pointings of ~4 hrs, targeting over 5000 HST and JWST-detected faint sources with 5 low, medium, and high-resolution dispersers covering 0.6-5.3 microns. Finally, JADES extends redward via coordinated parallels with the JWST Mid-Infrared Instrument (MIRI), featuring ~9 arcmin$^2$ with 43 hours of exposure at 7.7 microns and twice that area with 2-6.5 hours of exposure at 12.8 microns For nearly 30 years, the GOODS-S and GOODS-N fields have been developed as the premier deep fields on the sky; JADES is now providing a compelling start on the JWST legacy in these fields.

JWST has discovered an early period of galaxy formation that was more vigorous than expected, which has challenged our understanding of the early Universe. In this work, we present the longest spectroscopic integration ever acquired by JWST/MIRI (t(obs) approximate to 51 hr). This spectrum covers the brightest rest-frame optical nebular emission lines for the luminous galaxy JADES-GS-z14-0 at z = 14.18. Most notably, we detect [O III]lambda lambda 4959, 5007 at approximate to 14 sigma and H alpha at approximate to 4 sigma with these ultradeep observations. These lines reveal that JADES-GS-z14-0 has low dust attenuation with a recent star formation rate of SFR approximate to 8 +/- 2M(circle dot) yr(-1), star formation rate surface density of Sigma(SFR) approximate to 20 +/- 5M(circle dot) yr(-1) kpc(-2), and ionizing photon production efficiency of xi(ion) approximate to 10(25.3 +/- 0.1) Hz erg(-1). Using standard strong-line diagnostics, we infer a gas-phase oxygen abundance of log(10)(O/H)+12 approximate to 7.5 +/- 0.2 (approximate to 6%Z(circle dot)), carbon-to-oxygen ratio of [C/O] approximate to -0.4 +/- 0.2, ionization parameter of log(10)(U)greater than or similar to-2.4 , and density of nH approximate to 690 +/- 200 cm(-3). Using detailed photoionization modeling, we instead derive log(10)(O/H)+12 approximate to 8.5(-0.4)(+0.4) (approximate to 60%Z(circle dot)), log(10)(U)approximate to-1.4(-0.4)(+0.3) , and n(H)approximate to 540(-320)(+520)cm(-3) . The inferred properties of JADES-GS-z14-0 are similar to those measured for similarly luminous galaxies at z > 10 with previous MIRI/Spectroscopy, such as GHZ2/GLASSz12, GN-z11, and MACS0647-JD1. These results suggest extreme ionization conditions and rapid metal enrichment less than 300 Myr after the Big Bang. Existing simulations are unable to reproduce the empirical and inferred properties of JADES-GS-z14-0. This work demonstrates an important step toward understanding the formation of the first stars and heavy elements in the Universe. Future work will focus on the detection of the rest-frame optical continuum and its interpretation for the stellar population properties of JADES-GS-z14-0.

We report a galaxy overdensity candidate at z approximate to 10.5 in the JWST Advanced Deep Extragalactic Survey. This overdensity contains 18 galaxies with consistent photometric redshifts within 8 comoving Mpc in projection. The galaxy number density is 4 times higher than the field expectation, accounting for one-third of comparably bright galaxies and nearly 50% of the total star formation rate (SFR) at 10 < z(phot) < 12 in the GOODS-S field. Galaxies in the overdensity more frequently have close companions or substructure, with one-third showing such features within 1 kpc at consistent photometric redshifts, implying enhanced interactions. Most galaxies have stellar masses of 0.6-3 & times; 10(8) M-circle dot, half-light radii of similar to 200 pc, and SFRs of similar to 5 M-circle dot yr(-1). Their stellar masses and SFRs are slightly higher than those of field galaxies, but remain broadly consistent with typical high-redshift scaling relations. Two compact objects show possible Balmer breaks, suggestive of evolved stellar populations or little red dots. We find tentative evidence for a spatially varying Ly alpha transmission inferred photometrically, consistent with an emerging ionized bubble. This overdensity provides a rare opportunity for probing the environmental impact on galaxy evolution and the onset of cosmic reionization within the first 500 Myr.

We investigate how core-collapse supernova (CCSN) rates trace the star-formation rate densities (SFRDs) over the redshift range 0 ≤ z ≤ 5. For this we use new high-redshift results from the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES) Transient Survey (JTS, see the companion paper by DeCoursey et al. 2026), together with published CCSN rates. Using the observed CCSN rates to constrain the CCSN production efficiency relating SFRDs to CCSN rates, we examine how the inferred connection between star formation rates and CCSN production efficiency depends on the stellar initial mass function (IMF) and the adopted CCSN progenitor mass range. We find that the observed CCSN rates are consistent with dust extinction-corrected UV+IR based SFRDs for plausible CCSN progenitor masses. Using the observed CCSN rates to directly reconstruct the cosmic star-formation history, we recover a peak at z ∼2, in agreement with galaxy luminosity-based determinations. Allowing the IMF to evolve with redshift has only a modest impact when SFRD estimates are treated consistently, indicating that CCSN rates are not as sensitive to the change of IMF as might be assumed. Adopting higher SFRDs that include a dust-obscured population of faint millimeter sources implies a substantial and increasing fraction of missing, dust-obscured CCSNe at higher redshifts. Although the inferred fraction of CCSNe missed by the surveys depends on the adopted CCSN production efficiency, we find an increasing fraction of supernovae missed due to obscuration, rising from modest values at low redshift to a peak at z ∼2, and remaining substantial toward z ∼5.

According to the leading cosmological model, a first generation of stars called Population III (PopIII), condensed almost entirely out of hydrogen and helium, must have initiated the creation of all heavier chemical elements. We report the detection of ionised hydrogen (Hγ_4342) with a signal-to-noise ratio of S/N=5.9 in a region about 3 pkpc (projected) north-east from the z 10.6 galaxy GN-z11, where line emission compatible with doubly ionised helium (HeII_1640) has been found. Our new JWST/NIRSpec-IFU G395H data confirm the authenticity of the previous detection at a redshift of z_ Hγ=10.5862±0.0003. Hδ is marginally detected (S/N∼2). No metal lines are detected in our observations spanning λ_ rest=0.25-0.45μm. We derive a 3σ upper limit on the gas phase metallicity of 12+log(O/H)<7.0 (Z_ gas<0.02 Z_⊙). Through comparison with NIRCam imaging, we constrain a lower limit on the equivalent width of EW_0(Hγ)>350Å. We compare our emission line constraints to model predictions and find them compatible with photoionisation by PopIII stars, possibly intermixed with next-generation (PopII) stars. We infer an upper limit on the dynamical mass of M_ dyn≲3×10^8M_⊙. Our data provide novel support for the presence of PopIII stars nearby GN-z11, 440 Myr after the Big Bang.

Massive star-forming clumps are a prominent feature of high-redshift galaxies and are thought to trace gravitational fragmentation, feedback, and bulge growth in gas-rich disks. We present a statistical analysis of clumps in similar to 3600 galaxies spanning 2 less than or similar to z less than or similar to 8 from deep JWST/NIRCam imaging in the JADES GOODS-South field. Clumps are identified as residual features after subtracting smooth S & eacute;rsic profiles, enabling a uniform, rest-frame optical census of subgalactic structure. We characterize their physical properties, size-mass relations, and spatial distributions to constrain models of subgalactic structure formation and evolution. We find that clumps in our sample are typically low-mass (10 similar to 7-8M circle dot), actively star-forming, and show diverse gas-phase metallicity, dust attenuation, and stellar population properties. Their sizes and average pairwise separations increase with cosmic time (toward lower redshift), consistent with inside-out disk growth. The clump mass function follows a power law with slope alpha=-1.50-0.17+0.19 , consistent with fragmentation in turbulent disks. We find a deficit of relatively young clumps near galaxy centers and a radial transition in the size-mass relation: outer clumps exhibit steeper, near-virial slopes ( Re proportional to M*similar to 0.3 ), while inner clumps follow flatter trends ( Re proportional to M*similar to 0.2 ), consistent with structural evolution via migration or disruption. These results provide new constraints on the formation, survival, and dynamical evolution of clumps, highlighting their role in shaping galaxy morphology during the peak of cosmic star formation.

The JADES Transient Survey (JTS) identified 83 supernova (SN) candidates in the JADES Deep Field, a ∼25 arcmin^2 region with deep (∼30 mag) multi-band, multi-epoch JWST/NIRCam coverage. We use this sample to derive the first volumetric core-collapse (CC) SN and Type Ia (SN Ia) rates in the z∼2-5 range. Many of these SNe are photometrically classified from single-epoch photometry (i.e., single spectral energy distributions (SEDs)), so we simulate and classify ∼23,000 CC SN and SN Ia mock SEDs over 0.7≤z≤5 to quantify single-SED classification accuracy as a function of redshift. We report consistent rates for two samples: (1) the full JTS sample, including single-SED classifications, and (2) the "gold" sample, restricted to sources classified spectroscopically or with multi-epoch light curves. In units of 10^-4 CC SNe yr^-1 Mpc^-3, the full sample CC SN rates are 6.2^+2.2_-1.7 at 2.06≤z<2.78 and 4.1^+1.5_-1.1 at 2.78≤z≤5.06, broadly consistent with the expectations from the galaxy luminosity-based measurements of the cosmic star formation rate density. Our full sample rates tentatively exhibit the predicted decline beyond cosmic noon, providing the first direct observational indication of this behavior. A companion paper, C. Vassallo et al., presents a more detailed comparison. We measure a full sample SN Ia rate of 0.3^+0.3_-0.2×10^-4 SNe Ia yr^-1 Mpc^-3 at 1.92≤z<3.60. Future high-z SN surveys with JWST and the Roman Space Telescope will expand these samples and provide more robust constraints on SN rates in the high-z Universe.